From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f41.google.com (mail-la0-f41.google.com [209.85.215.41]) by kanga.kvack.org (Postfix) with ESMTP id 2BE9E6B006C for ; Wed, 14 Jan 2015 04:45:41 -0500 (EST) Received: by mail-la0-f41.google.com with SMTP id hv19so7146574lab.0 for ; Wed, 14 Jan 2015 01:45:40 -0800 (PST) Received: from mail-lb0-x235.google.com (mail-lb0-x235.google.com. [2a00:1450:4010:c04::235]) by mx.google.com with ESMTPS id qz8si14069160lbc.116.2015.01.14.01.45.39 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 14 Jan 2015 01:45:40 -0800 (PST) Received: by mail-lb0-f181.google.com with SMTP id l4so6989234lbv.12 for ; Wed, 14 Jan 2015 01:45:39 -0800 (PST) Date: Wed, 14 Jan 2015 12:45:38 +0300 From: Cyrill Gorcunov Subject: Re: [PATCH 1/2] mm: rename mm->nr_ptes to mm->nr_pgtables Message-ID: <20150114094538.GD2253@moon> References: <1421176456-21796-1-git-send-email-kirill.shutemov@linux.intel.com> <1421176456-21796-2-git-send-email-kirill.shutemov@linux.intel.com> <20150113214355.GC2253@moon> <54B592D6.4090406@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54B592D6.4090406@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: "Kirill A. Shutemov" , Andrew Morton , Hugh Dickins , linux-mm@kvack.org, Pavel Emelyanov , linux-kernel@vger.kernel.org, Benjamin Herrenschmidt On Tue, Jan 13, 2015 at 01:49:10PM -0800, Dave Hansen wrote: > On 01/13/2015 01:43 PM, Cyrill Gorcunov wrote: > > On Tue, Jan 13, 2015 at 09:14:15PM +0200, Kirill A. Shutemov wrote: > >> We're going to account pmd page tables too. Let's rename mm->nr_pgtables > >> to something more generic. > >> > >> Signed-off-by: Kirill A. Shutemov > >> --- a/fs/proc/task_mmu.c > >> +++ b/fs/proc/task_mmu.c > >> @@ -64,7 +64,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) > >> data << (PAGE_SHIFT-10), > >> mm->stack_vm << (PAGE_SHIFT-10), text, lib, > >> (PTRS_PER_PTE * sizeof(pte_t) * > >> - atomic_long_read(&mm->nr_ptes)) >> 10, > >> + atomic_long_read(&mm->nr_pgtables)) >> 10, > > > > This implies that (PTRS_PER_PTE * sizeof(pte_t)) = (PTRS_PER_PMD * sizeof(pmd_t)) > > which might be true for all archs, right? > > I wonder if powerpc is OK on this front today. This diagram: > > http://linux-mm.org/PageTableStructure > > says that they use a 128-byte "pte" table when mapping 16M pages. I > wonder if they bump mm->nr_ptes for these. It looks like this doesn't matter. The statistics here prints the size of summary memory occupied for pte_t entries, here PTRS_PER_PTE * sizeof(pte_t) is only valid for, once we start accounting pmd into same counter it implies that PTRS_PER_PTE == PTRS_PER_PMD, which is not true for all archs (if I understand the idea of accounting here right). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org